Slow swim CV

Great question. I don’t tend to pay attention to heart rate for swimming, but rather perceived exertion and pace-paced zones. If you loose your form, that will result in you both slowing down and also working at a higher exertion because you are working to overcome your form. What I suggest is introducing a pull buoy into your workouts when you are working the lower zones. It does a few things for you: 1) It mimics the experience of being in a wetsuit with buoyancy under your legs. 2) It will help improve your form and mimimize the drag in the water. 3) It will therefore allow you to twin at a lower perceived exertion, therefore lower heart rate, lower zone. My CV is around 2:15, but with the pull I can comfortably do Z1 at this pace and then if I push my pace, I can do Z3 at 2:00. The range of paces for the zones in the swim will be quite narrow, but you’ll see huge improvement with a focus on good form. And even a Z3/4 swim will not be nearly as taxing as a similar run or bike so you can accomplish quite a lot during the off-season on your aerobic system through swimming. Another tip is to alternate with breast stroke during your warm-up and cool down. It’s a slower paced stroke, but a good one to master if the swim is anxiety provoking. You can always use breast stroke to get your bearings, site, and navigate buoys.